基于SEER数据库分析直肠癌外放疗后第二原发膀胱癌的发生风险与预后

Risk and prognosis of second primary bladder cancer in patients with rectal cancer after external beam radiation therapy:a SEER based study

目的分析直肠癌(RC)患者围手术期外放疗(EBRT)对第二原发膀胱癌(SPBC)发病风险及预后的影响。方法通过监测、流行病学和最终结果(SEER)数据库回顾性筛选1973年1月1日至2015年12月31日期间病理确诊RC患者51649例。利用SEER*Stat软件,采用泊松回归计算标准化发病率(SIR)。使用R软件,采用Fine-Gray竞争风险回归分析评估RC患者发生SPBC的累积发生率。最后使用倾向评分匹配Kaplan-Meier法评估SPBC患者的生存结局。结果在51649例RC患者中,15612例患者同时了接受手术和EBRT,而36037例患者仅接受手术治疗。总计随访30年,放疗组(RT组)SPBC的累计发病率为4.50%,无放疗组(NRT组)为2.20%。RT组的SIR高于普通人群(SIR=1.43,95%CI:1.24~1.64,P<0.050)。竞争风险回归分析显示,接受放疗与更高的SPBC发生风险相关(HR=1.49,95%CI:1.13~1.95,P=0.004)。RT组和NRT组经倾向评分匹配后合并的SPBC患者的生存分析结果显示,两组患者10年总生存期的差异有统计学意义(62.8%vs 72.7%,P=0.010)。此外,RT组(27.7%vs 40.4%,P=0.005)和NRT组(24.2%vs 35.1%,P<0.001)合并SPBC患者的10年总生存期均显著低于仅诊断原发膀胱癌患者。结论放疗是RC长期生存患者发生SPBC的重要危险因素,且可能与合并SPBC患者的不良预后有关。

Objective To explore the impact of perioperative external beam radiation therapy(EBRT)on the risk and prognosis of second primary bladder cancer(SPBC)in rectal cancer(RC)patients.Methods We retrospectively reviewed 51,649 RC patients diagnosed by pathology from January 1st,1973 to December 31st,2015,utilizing the SEER database.Standardized incidence ratio(SIR)was calculated using Poisson regression and SEER*Stat software.The cumulative incidence of SPBC in RC patients was assessed through Fine-Gray competitive risk regression analysis using R software.Finally,the propensity score matching Kaplan-Meier method was employed to evaluate the survival outcomes of SPBC patients.Results Among the 51649 RC patients,15612 underwent both surgery and EBRT,while 36037 underwent surgery alone.After 30 years of follow-up,the cumulative incidence of SPBC was 4.50%in the radiotherapy(RT)group and 2.20%in the non-radiotherapy(NRT)group.The SIR in the RT group exceeded that of the general population(SIR=1.43,95%CI:1.24-1.64,P<0.050).Competitive risk regression analysis indicated that RT was associated with a higher risk of SPBC(HR=1.49,95%CI:1.13-1.95,P=0.004).Survival analysis of SPBC patients combined after propensity score matching between the RT group and NRT group showed a statistically significant difference in 10-year overall survival between the two groups(62.8%vs 72.7%,P=0.010).Additionally,the 10-year overall survival in patients with SPBC,both with(27.7%vs 40.4%,P=0.005)and without(24.2%vs 35.1%,P<0.001)RT,was significantly lower than that in patients diagnosed with only primary bladder cancer(OPBC).Conclusions RT emerges as a pivotal risk factor in SPBC for RC patients with long-term survival,potentially contributing to a poorer prognosis in patients with SPBC.